Abstract

Using a phenomenological approach, we demonstrate that a giant mechanically-mediated electrocaloric effect can be obtained in ultrathin ferroelectric SrRuO3/BaTiO3/SrRuO3capacitors at room temperature. Our results show that the electrocaloric properties of such capacitors can be systematically tuned by applying an external stress. The depolarizing field, whose effect is usually ignored in the literature, is found to be detrimental to the electrocaloric response, especially for the thinner films. Moreover, a remarkable enhancement and broadening of the electrocaloric response can be achieved in relatively thick films under compressively loaded conditions compared with the unloaded case.

The authors gratefully thank V. Garcia, P.-E. Janolin, I. A. Kornev, and L. Bellaiche for fruitful discussions and the anonymous reviewer for his/her suggestions to improve the manuscript. Y.L., I. C. I, and B. D. acknowledge the ANR for financial support through NOMILOPS (ANR-11-BS10-016-02) project and thank the China Scholarship Council (CSC) for funding Y.L.’s stay in France. X. J. L. and Y. L. thank the National Science Foundation of China (NSFC No. 51372195), the Ministry of Science and Technology of China through a 973-Project (No. 2012CB619401) and “One Thousand Youth Talents” program for support. D. C. L. acknowledges support 361 by Deutsche Forschungs-gemeinschaft (Lu 729/15). This work is also supported by the European Commission within FP7 Marie Curie Initial Training Network “Nanomotion” (grant agreement no 290158).